Shop TalkRick Mack's Guide to Finishing Woodie Wood:
Choices, Procedure and Style
Restoring a woodie is largely a contemplative experience. Each of us spends an inordinate amount of time just staring at our woodie, absorbed and thinking, trying to figure out just how some aspect of the project should look...sound...feel...or? Most of you already know what I mean. This think and dream time, hard to separate the two, is an integral part of the fun but it also can be very frustrating at times, especially making the final choices and decisions. Hopefully, the following information will make your finishing choices easier.
Choosing the right finish for YOUR woodie depends on several important considerations: Is YOUR woodie being restored to original? Will it be shown and judged for points on its originality? Perhaps it will be a 'driver' or a 'street rod'? Do you have small children? Dogs? Where do you live? California? Alaska? North Dakota? How about the Gobi Desert? Do you like 'super shiny'? Do you have access to spray facilities? What is YOUR vision for YOUR woodie?
What are the choices for finishes?
In the beginning there was varnish. An excellent and ancient (Stradivarius mixed his own!), tough, reliable and, most important, EASY to apply wood finish. Varnish flows out so smooth all by itself. You can brush it, spray it, or rub it on with a rag. It is very adaptable and beautifully lustrous after six, eight or even more coats. Anyone can use it and apply it at home but it does take time, especially the thorough sandings between coats. Ford, GM, Chrysler and every other company that originally produced woodies used varnish as their primary finishing material. Varnish was simply the best product available for exterior finishing during the twenties, thirties and forties, even into the fifties and sixties. Good stuff then, good stuff now.
Varnish comes in GLOSS and SATIN. Woodies came in gloss from the factories. There are woodies that still have their original varnish today and sometimes this varnish appears to be satin but that most likely is due to the effects of age.
The only real drawback to varnish was DURABILITY or the lack of it, especially with the earlier formulas. As all woodie owners have experienced, varnish deteriorates under sun, rain and abrasion resulting in cracking, splitting and peeling of the finish, leaving the wood unprotected. A woodie kept in daily use with a varnish finish will need to have a sanding and revarnish job every year or two in order to stay sharp. This constant maintenance problem was the main reason for the ultimate demise of the woodie as a production car. Yes, they were difficult and expensive to produce as well but the buying public's inability and/or unwillingness to keep sanding and varnishing the wood always held sales down-especially after the steel bodied wagons appeared!
Much has changed since the days when woodies were production cars. Varnish, for one, has improved greatly now having excellent ultra-violet, UV, protection and much tougher formulas, translating into much better durability and longevity. Modern varnish makes a wonderful finish. Probably the greatest difference between 'then' and 'now', however, is the simple fact that, today, few woodies are used as all-weather daily drivers! All things considered, modern varnish makes an excellent choice for your pampered woodie.
Many fine brands of varnish are on the shelf. I like Z-SPAR FLAGSHIP and EPIPHANES for their great UV protection. I like Z-SPAR CAPTAINS and INTERLUX SCHOONER for their wonderful warm, golden tone and these also have good UV protection. Always read the instructions of the brand you choose. Also make sure that you have the correct thinner to match the varnish. It is best to buy varnish by the quart. The gallon is less expensive but it will 'skim over' and become useless long before you get to the bottom of the big can!
Applying varnish can be a very enjoyable, Zen experience! We'll get to that soon.
Basically, these are automotive clear-coats and they are REALLY TOUGH! They require a catalyst, they must be sprayed and they can be TOXIC! You will need a ventilated spray booth, quality respirator and an inexpensive spray suit would be advisable as well. If you can put this package in place, you can quickly shoot a lifetime, super-durable finish on your wood and spray THREE coats at a time! Urethane glosses out like polished glass and cures out in a few days as hard as nails. Yes, it IS flexible too! (How'd they do that?) All automotive paint companies produce a catalyzed urethane for clear coats. I have been using DUPONT V-7600S with terrific results. No tougher or more glossy finish is available! I do love varnish but the catalyzed urethanes get my vote for the best finish that you can buy! However, because of the high VOC and toxic nature of this material, it is not for everyone and it is not readily available in California. At least it is not supposed to be? Check with your local auto paint store or local body shop.
Oh yes, this is real high-tech stuff and you MUST follow the manufacturers instructions precisely! Urethanes are NOT ZEN!
I understand that some similar finishing materials are now available in 'water-base' but I have no experience to date with any of these products. Eventually, all finishes will have to be water-based and environmentally friendly. A very good idea, especially if these products can be made to be as tough as the solvent-based finishes of which I am familiar. Time will tell.
There is another class of finishes known as POLYURETHANES. They are readily available at all hardware stores, they apply with a brush or spray very similar to varnish products but they are different chemically from the varnishes. Some are water-based too. They are very durable and easy to apply, however, they do not have any tone. Polyurethanes are very clear, some even have a slightly cold or blue cast to them which I find unsightly on wood. I much prefer the appearance of varnish but if you are looking for a super clear finish that can be applied with a brush at home, polyurethane may be for you. If you are going to use polyurethanes, you can follow the same instructions below for sanding and applying varnish.
Wood Preparation, Good Words, Meditation & Sanding
No matter which finish you choose for your woodie, you will need to sand the wood thoroughly before applying the finish. This process is always the same, today as yesterday, no short cuts. For new wood or old wood in GOOD CONDITION, use a random orbital sander (Dewalt makes the best, you can't miss 'em, they are yellow!). Start with 80 grit to get out any heavy scratches or divits and to get off the dark, weathered top layer of the wood. Wear a dust mask! After the 80 grit, move on to sanding all the wood again with 100 grit which gets rid of the scratches left by the 80 grit then sand all again with 150 grit to remove scratches left by the 100 grit. In most cases, sanding down to 150 grit is more than adequate. Maybe sand down to 180 grit if you are obsessive. Further sanding with finer sandpaper on hardwood becomes an exercise in futility and can actually smooth the wood so much that it has no 'tooth' to hold the finish! You should dust off the wood between sanding grits so no errant pieces of sand from the previous grit will remain to put those nasty little circular scratches into your wood.
You must be sure to look very carefully for any remnant heavy scratches, they will appear under good light after you have finished sanding with 150 grit. If you do not find them and re-sand them out now, they will surely be visible after you have applied the finish. Take your time here.
If you need to bleach your old wood, do your full regimen of sanding first! After bleaching, you can only sand with 180 grit or 220 grit by hand to smooth out the fuzz raised by the bleaching process. The bleached layer of the wood is not very deep and it sands off easily. Read more about wood bleach in my separate instructions for bleaching.
When sanding softwoods such as mahogany, you will need to sand down to 180 grit for sure and perhaps down to 220 grit. If you plan to stain your mahogany panels the extra fine sanding will assure that there will be no tiny swirl marks left to trap the stain and look ugly under the varnish. Remember: paneling veneer is very thin. Be careful not to sand through it!
After sanding thoroughly through the grits with the random orbital sander, you might consider taking some 180 grit or 220 grit sandpaper in your hand and smoothing out the edges and corners of the hardwood and the difficult to reach inside corners. note: Varnish or any other finish will NOT stick well to a blade edge. Always ease the edges at least a little! Yes, it is best to sand 'with the grain' but you knew that.
Your new wood and old wood should now be ready for application of the finish.
One exception: If you have bleached any of your wood, it most likely will need to have some toning done as the A&B type wood bleaches tend to leave the wood looking more like bleached bone found on the desert than warm maple, birch or ash.
How to tone the wood -
Go to your local art store and buy some oil based artists paint tubes. I use 'raw sienna' with a little 'burnt sienna' stirred up in a mix of 1/3 mineral spirits, 1/3 PURE-BOILED linseed oil and 1/3 lacquer thinner in a quart container. Squeeze a couple of toothpaste globs of the raw sienna into the mix and then a small squeeze of the burnt sienna, just a little now, put on the top and shake it up. Mix it very thoroughly. You will have to shake it up periodically during use as the color settles out fairly quickly. Keep handy another cup of the same thinner mix without any color added. Mix some of the colored mix with some of the clear thinner mix and apply with a brush
to some of your bleached wood. Let it sit and soak for a few minutes then wipe it off with a clean rag. Try a thin mix first and add more color to the mix if you need it. Remember: THIS IS ART, NOT SCIENCE! With some practice and experimentation, you should be able to match the color of the bleached old wood with the color of the new wood. You can do this so well that old and new woods will be indistinguishable from one another! Note: Nothing can be done about weather-checking cracks or dry rot. These injuries are permanent unless you replace the wood pieces with this type of damage. Always try a test piece of wood first too and let the stain/toner dry for a couple of days before applying your finish.
Another option for adding tone to your wood is SHELLAC. This is a natural finishing material that comes in 'blond' and 'amber' tones right off the shelf. It makes a wonderful sealer under varnish and even catalyzed urethane as long as IT DOES NOT HAVE ANY WAX in it. Read the labels. You want it WAX FREE. The amber tone is very warm, again experiment. You can thin shellac with denatured alcohol. Do not use it under the POLYURETHANES!
If you wish to stain your mahogany paneling, there are a myriad of commercial stains available at your hardware or paint store. I have used many different brands, both water-based and solvent-based, most have worked very well. Pick a stain and try a test where it will not show. You might have to mix two stains together to achieve your desired color. Experiment!
A trick -
If you only want to darken your mahogany slightly, try setting all of your paneling out in the sun for an hour. Be sure to evenly expose all pieces as any shaded area will remain lighter! This process works be itself in your shop if you leave the paneling exposed to light or even air for a long time. Keep it wrapped up until you are going to work on it.
Are You Ready?
Let's Try varnish. You'll Need Good Light
Start with a 1-1/2 inch brush. It can be an inexpensive one since we are going to first be applying varnish coats to obtain a 'build', meaning some thickness of coats on the wood before we worry about sanding it smooth. You can use a throw-away 'sponge' brush on the flat paneling but sponges do not work well on the structural wood parts with edges, curves, reliefs and corners.
Pour some varnish from your quart can into a separate cup. Estimate how much you are actually going to use. Never varnish directly from the can as doing so will quickly contaminate your remaining varnish with 'crud' known as 'inclusion bodies' which will lump up your subsequent coats. If you have varnish left over in the cup when you are done finishing for today, paint it on the dog house or maybe on the hidden areas of your wood or on the backside of your paneling... Don't pour it back in the can!
Before you start varnishing, it is a very good idea to clean off all of the wood that you have carefully laid out to varnish. Try using a soft dust brush first then a vacuum cleaner or air blower (Blowing the wood dust around can be a problem however), then wipe with a cotton rag dampened with paint thinner, let dry and, finally, go over the wood completely with a tack cloth. The cleaner you can get the wood, the better the varnish job will be!
There are at least two different theories about the first varnish coat.
I feel that the first coat should be thinned as much as 50% with the appropriate thinner for the varnish that you have chosen. Read the labels on the can regarding thinners. The theory is that the first coat will soak way into the wood-be especially thorough wetting the open end grain and seal it against moisture. Some woodie manufacturers actually soaked the wood in varnish to seal it!
Another theory is to use the varnish straight from the can without thinning. Perhaps reading the instructions on the can is the best way to go about this. Most brands recommend thinning about 20% on the first coat.
With my 1-1/2' brush, I apply a 50/50 thinned mix of varnish, working quickly to get the wood thoroughly coated. Work a single piece of wood or a single unit such as a door at one time so you can be thorough and maintain control. After you become adept at varnishing you can work larger areas or multiple units. You may brush cross-grain or any way you choose to get the varnish onto the wood and once it is completely wet, shift to quickly brushing out the varnish WITH THE GRAIN so it will flow out smoothly. Thoroughly saturate the end grains with this thin coat!
If you are working on an assembled unit such as a door, pick a piece of wood at the top, varnish it completely, stroke it out with the grain then move on to the next attached piece of wood and follow the same procedure. Try to keep a 'wet edge' when varnishing, not letting the varnish dry before continuing on from the last point with new varnish. This takes a little practice as you must move down a door in several directions at the same time. This is why you will need to work quickly. However, varnish is really forgiving and multiple coats will cover any missed spots. Try NOT to leave too many missed spots during each coat. After a couple of coats, you will gain more control and find your own rhythm and style of applying varnish.
Moving on -
After you have varnished your ready wood pieces with the 50/50 thinned mix, let the varnish dry for eight or ten hours then go right back and apply a second coat of the same thinned mix. As long as you do not wait any longer in between the first and second coat, the second coat will stick just fine. If you wait a day, you will need to sand lightly with 220 grit or a scotch pad so the next coat will stick. Let the second coat dry completely, perhaps taking two days. Now sand LIGHTLY with 220 grit and follow up with a scotch pad to completely dull the surface for the next coat to stick. These two thinned coats of varnish are not yet thick enough to sand aggressively.
Clean the sanded surface with a thinner rag, then a tack cloth and mix up a third coat of varnish. This time you need to mix 25% thinner with 75% varnish. Do read the instructions on the can regarding just what to use as a proper thinner for your selected varnish. Apply a third coat of the 75/25 varnish/thinner mix and let dry completely. Scuff thoroughly with a scotch pad, clean the wood and apply a fourth coat of the 75/25 mix. Let it dry completely. Scuff this fourth coat thoroughly with the scotch pad.
For the fifth coat and for subsequent coats, you want to thin the varnish 10% to 20% depending on the ambient temperature. You can use varnish at full strength here but it will not flow well if the weather is too warm. When your brush 'drags', you need to thin your varnish. Varnishing is a matter of 'feel' and varies from person to person.
After you have five or six coats of varnish on your wood, you can begin to sand more aggressively with 320 or 400 grit sandpaper between coats. Be careful of sanding too much on the edges as it is easy to sand through to bare wood. It is a good idea to avoid sanding the edges with sandpaper and just touch them lightly with a scotch pad to give them a 'tooth'. The more coats you have, the cleaner you need to get your wood before applying the next coat of varnish. When you have successfully applied seven or eight coats, you are ready to apply a 'last' coat. Wipe that wood really clean and apply a last coat thinned at about 15%. When dry, check it out. How does it look? did you get a lot of junk in it? You can sand out a few lumps with 600-1000 grit wet and dry sandpaper, then rub it out with polish but if this coat has too many 'inclusion bodies', you will need to sand and apply another 'final' coat. Use your best brush on these last coats and clean them after use with lots of mineral spirits/paint thinner but NOT lacquer thinner.
Much of this varnish work is a learning experience and requires some getting used to before finding your own rhythm and style. Deciding on when the job is done is kind of a judgement call as well. You are done when you are satisfied that the varnish looks good and feels good to you.
There are other approaches to thinning, to sanding and to varnishing. I have one friend who always uses varnish straight from the can without thinning at all! He does put it into a separate cup before applying. He also sands solely with 150 grit in between coats, a grit which seems a little too rough for me but his varnish work is always superb! Another friend, who restores wooden boats, only uses EPIPHANES varnish and thins the first few coats 50/50 then applies some at 60/40 then some at 75/25 until he reaches 16 or 18 coats-all with a sponge brush! His boats are spectacular! These differences in procedures and approaches are really a tribute to just how versatile and forgiving varnish is! You will have to find a varnish regimen that works for you.
The final varnish coats can be sprayed of course, for that matter, all of the varnish coats can be sprayed. I feel that the beginning coats are easier to control with a brush during application. The brush also allows you to fully saturate and better seal the end grains of the wood.
Applying the Not-Zen, High-Tech Stuff: Urethanes
Urethane finishes can be applied directly to the wood but I recommend using some kind of sealer first-especially on the soft mahogany panels. Many sealers are available commercially: WATER-WHITE LACQUER, ACRYLIC, EPOXY and SHELLAC to name a few. I have used all of these types with excellent results. I prefer to use SMITHS 'Clear Penetrating Epoxy Sealer' (CPES) which is a two-part, A&B chemistry mixed 1: 1 for application. It is very thin and soaks way into the wood and seals it against water quite well. All types of finish can be applied over it.
Always test sealers and finishes first before using on stained paneling -
After applying a sealer according to the manufacturers instructions, if you choose to use one, let it dry, sand smooth with 220 grit to 400 grit sandpaper and clean the wood as dust-free as possible. Same as you would do before applying varnish. During the dust-off of the wood, it should be moved into a suitable spray booth and tacked off again.
Following the manufacturers instructions exactly, mix the URETHANE that you have chosen. Mix only as much as you think you will need, perhaps a pint or a quart. This material IS expensive!
Note: Urethane is ABSOLUTELY CLEAR. NO TONE. If you wish to have your wood appear warm and golden like it does with a varnish finish, you will need to tone the urethane with DMX dyes which are available through your local auto paint stores. These dyes are known as 'RADIANCE' colors at the auto paint store. You only need a small amount of DMX #212 RED and DMX YELLOW (They only make ONE yellow). Take your own little bottles with good, tight tops to the paint store. You will need no more than an ounce of each color. The DMX RED is more intense than the DMX YELLOW.
Try a mix of one drop of red and four drops of yellow to each pint of your clear urethane. Use a SMALL drop dropper, not a BIG drop dropper! Drops can vary greatly in size, try to standardize the drop size. Add more color if you need it. Do a test first on some scrap wood. TEST, TEST, TEST!
Put on your respirator, go into the booth, load your spray gun with your mixed urethane and spray on three coats of the urethane waiting about 15 minutes in between coats for the clear to 'flash'. Let the finish dry for at least a day, maybe two, then wet sand with 400 grit to 600 grit using a rubber pad under the sandpaper-'block sanding'. Watch those edges, don't sand through the finish on them! Clean and tack the wood, spray three more coats in the same manner as the first three coats. The soft mahogany might need an extra shoot of two or three coats as it is very absorbent. Let the clear dry for a couple of days. You might have to sand out a few 'inclusion bodies' with 1000 grit or 1500 grit and then polish out the wood with fine polishing compound. This final step takes some time but can make for a super smooth and glossy finish-just like a custom paint job! Varnish can also be polished out in the same fashion but it takes longer to cure before it can be successfully polished or hand rubbed out.
If you are unfamiliar with spraying automotive paints, you should seek some professional help or choose to use brushed on varnish as a finish. The urethane finish is super tough and glossy but it IS high tech and requires some advanced knowledge to use properly.
One of the above methods of finishing should work for you. It is not a bad idea to find some wood to practice on before you start on your woodie.
Good luck and good finishing!
Rick Mack Enterprises
Restorations and all new wood sets & parts for 1949-51 Fords & Mercurys
© 1999,2000 Rick Mack. Full copyright of the "Rick Mack's Woodie Refinishing Guide" (RMWRG) is held by Rick Mack.
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